bolts › machine bolts
AN174-21A
Aeronautical Standard Machine Bolt
Description
length: 2-5/32", grip: 1-11/16", thread: 1/4-28, cadmium plated steel undrilled shank
Specifications
| Fastener Length | 2.140 inches minimum and 2.187 inches maximum |
|---|---|
| Features Provided | Finished head |
| Grip Length | 1.671 inches minimum and 1.703 inches maximum |
| Hardness Rating | 26.0 rockwell c minimum and 32.0 rockwell c maximum |
| Head Height | 0.140 inches minimum and 0.172 inches maximum |
| Head Style | Hexagon Head |
| Length | 2 3/16 |
| Material | Steel |
| Material Specification | Mil-s-5626 mil spec 1st material response or mil-s-6049 mil spec 2nd material response or mil-s-6050 mil spec 3rd material response or mil-s-6098 mil spec 4th material response or mil-s-6758 mil spec 5th material response or ams 6300 assn std 6th material response |
| Min. Tensile Strength (psi) | 125000 pounds per square inch |
| Surface Finish | 63.0 microinches bearing surface of head, 63.0 microinches grip |
| Surface Treatment | Cadmium and chromate |
| Surface Treatment Specification | Qq-p-416 ty 2 cl 3 fed spec all treatment responses |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.437 inches minimum and 0.516 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNF |
| Thread Size | 1/4 |
| Width Between Flats | 0.428 inches minimum and 0.440 inches maximum |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
Similar parts
Parts with matching key dimensions — often from a different standards family. Candidates for comparison only; verify the full specification before substituting.
- AN4DD21A AN 1/4-28 · 0.086 in · Hexagon Head · Aluminum
Looking for a specific part? Use the cross-reference lookup.
Catalog data updated 2026-07-05. Report a data error